In the last thirty days
Cubs lefty starter X: 4.85 K/9, 3.34 BB/9, 2.12 HR/9, 19.4% HR/FB, .224 BABIP, 5.16 ERA/5.56 ERA+/6.40 FIP/5.16 xFIP
Cubs lefty starter Y: 11.51 K/9, 2.38 BB/9, 3.57 HR/9, 23.7% HR/FB, .339 BABIP, 5.96 ERA/4.16 ERA+/6.89 FIP/4.25 xFIP
To be clear, I think both of these guys are better than this. That's not to say 'Good' or 'Should definitely start a playoff game'. They're both obviously struggling quite a bit, but them pitching well is a step above any of our other non-Gausman/Holmes options, so turning one or both of them into de-facto openers or short stint guys so that we can hypothetically chase wins with Aaron Civale and his 4.73 FIP seems like doing a little too much for pretty minimal upside.